The present invention relates to a recording head for use in a facsimile reception apparatus capable of recording in a plurality of line density modes.
In the conventional facsimile apparatus, a recording head is provided only with a recording electrode of a size in conformity with the finest line density required and by controlling the use of the recording electrode locally, various line density modes can be set. For example, in the case where simultaneous recording of 32 lines is performed, as shown in FIG. 1, a recording head 1 provided with 32.times.2 electrodes 2.sub.1 to 2.sub.64 is set at its finest line density, for example, at 8 lines/mm. These electrodes 2.sub.1 to 2.sub.64 are divided into two columns, namely, the odd-numbered electrodes 2.sub.1, 2.sub.3, . . . 2.sub.63 and the even-numbered electrodes 2.sub.2, 2.sub.4, . . . 2.sub.64 in the sub-scanning direction with a space of 0.25 mm therebetween, and the even-numbered electrodes 2.sub.2, 2.sub.4, . . . 2.sub.64 are spaced in the sub-scanning direction by 0.125 mm relative to the odd-numbered electrodes 2.sub.1, 2.sub.3, . . . 2.sub.63, respectively so that the space between the odd-numbered electrodes 2.sub.1, 2.sub.3, . . . 2.sub.63 are interpolated by the even-numbered electrodes 2.sub.2, 2.sub.4, . . . 2.sub.64. When recording is performed with 4 lines/mm line density, all of the 64 electrodes 2.sub.1 to 2.sub.64 are used, as shown by the shading in FIG. 2, and the signal voltages are respectively applied thereto by 64 drive circuits. The signals to be applied simultaneously to the 64 electrodes 2.sub.1 to 2.sub.64 are not the same. Referring to FIG. 2, for example, and in particular to an odd-numbered electrode, such as, the electrode 2.sub.1, a signal is applied to that electrode after a period of time required for the relative movement of the recording head in the main scanning direction by a distance l. This is the distance between the odd-numbered electrode (for example, 2.sub.1) and the succeeding even-numbered electrode (for example, 2.sub.2) in the main scanning direction. The same thing applies to the other electrodes 2.sub.3 and 2.sub.4, 2.sub.5 and 2.sub.6 . . . and 2.sub.63 and 2.sub.64. In other words, with respect to a scanning line, a signal is first applied to an even-numbered electrode and the applied signal is stored in the even-numbered electrode for a period of time which is determined by the distance l and the main scanning speed, and when the preceeding odd-numbered electrode comes to a position corresponding to the original position of the above-mentioned even-numbered electrode, the same signal is applied to the odd-numbered electrode for recording. In this case, when the even-numbered electrodes 2.sub.2, 2.sub.4, . . . 2.sub.64 are not used, 32 drive circuits will do for the electrodes, but in the spaces between the odd-numbered electrodes 2.sub.1, 2.sub.3, . . . 2.sub.63, there occur unrecorded blank portions, which reduces the image quality.
In the case where recording is performed with 8 lines/mm line density, the electrodes 2.sub.1 to 2.sub.32 are employed as shown in FIG. 3, and respectively different signal voltages are applied thereto by use of 32 drive circuits.
However, in the recording head of this type, the electrodes are disposed in conformity with the finest line density mode and by controlling the electrodes locally, each line density mode is set, so that numerous electrodes are required and accordingly, numerous drive circuits are required. Therefore, such recording head becomes expensive.